The present invention relates to ion exchangers in general, and more particularly to a method of and arrangement for regenerating by rinsing a particulate ion exchange resin contained in a fixed bed through which a liquid to be treated passes substantially vertically during a treating phase of operation of the arrangement.
In the performance of water treatment or purification, there are being currently used, among others, fixed bed ion exchangers which are being operated with an upward liquid flow during a treatment phase of operation, and with a downward liquid flow during a regeneration phase of operation. Although the fixed bed ion exchangers with this upward flow/downward flow operation have many advantages, such as a low consumption of chemicals, of water needed for operation, and of space, as well as the ease with which the operation of such arrangements can be automated, the heretofore known arrangements had an important disadvantage which stood in the way of their finding widespread acceptance and use, namely, that no resin backwashing was possible in the ion exchange column.
On the other hand, in known floating bed processes, the resin is conveyed for the backwashing thereof into a separate rinsing container. This backwashing process is rather expensive and thus suitable for economical use only in large and costly industrial installations, but not in installations intended for small-scale, such as household, use.